1. Field of the Invention
This invention relates to sulfur- and nitrogen-containing compositions and in a more particular sense it relates to those compounds having a thiocyanate salt/thiourea moiety adapted for use as a multifunctional additive in hydrocarbons. This invention relates also to hydrocarbon fuels and oils, especially lubricating oil compositions containing said multifunctional sulfur- and nitrogen-containing compositions.
2. General Background
The problem of deterioration of hydrocarbons has been the cause of principal concern in the formulation of hydrocarbon compositions such as fuels and lubricating compositions. Deterioration of hydrocarbons results in the formation of products which are corrosive to the metal surfaces with which the hydrocarbons come into contact.
In recent years it has been a common practice to incorporate into lubricating oils chemical additives which are capable of inhibiting the deterioration of oil and the formation of these harmful deposits. Such additives have generally been classified into various groups according to the manner in which they function to improve hydrocarbon oil. One group of such additives are the oxidation inhibitors which function to stabilize the oil against oxidative degradation. Another group of such additives are the corrosion inhibitors which counteract the corrosiveness of the products of oil degradation or passivate the metal surfaces against the corrosive action of such products. Still another group of such additives are the extreme pressure agents which function to enhance the load-carrying ability of the oil and thereby prevent or at least reduce the abrasive friction between the moving lubricated surfaces.
Two or more additives are often needed in a hydrocarbon fuel or oil to stabilize the hydrocarbon against formation of harmful degradation products. The incorporation of several different types of additives not only is costly, but is also dependent upon the compatibility of the additives with one another. Thus, it is known that additives which are effective separately may not be used in combination because of their incompatibility. A great deal of effort has recently been devoted to the development of so-called "multifunctional" additive, i.e., an additive which, by itself, is capable of imparting several desirable properties to a hydrocarbon fuel or oil. It will be readily appreciated that the use of such additive is highly advantageous from the standpoint of both economy and convenience.
3. Prior Art Publications
Sulfur- and nitrogen-containing compositions are stated to provide such desirable multifunctional activity to both fuels and lubricating oils. For example, in U.S. Pat. Nos. 2,619,464 and 2,680,759 it is reported that mineral lubricating oils containing small amounts of high molecular weight alkyl monothiocyanates, preferably C.sub.21 -C.sub.34 monothiocyanates as paraffin wax monothiocyanates, are resistant to oxidation and have a reduced tendency to corrode hard metal alloy bearings; and, 3,330,763 discloses the use of hydrocarbylamine salts of thiocyanic acid as load-carrying additives in lubricating oils.
It is, accordingly, an object of this invention to provide novel compositions of matter.
It is also an object of this invention to provide compositions adapted for use as multifunctional additives in hydrocarbons, particularly for fuels and oils.
It is also an object of this invention to provide compositions useful as corrosion, oxidation inhibitors and/or dispersants in hydrocarbon lubricating oils.